1912
MARSTON TAYLOR BOGERT AND HORACG H. HOPKINS
VOl. 46
salts, the mono-acetate and monobenzoate and the dianilino derivative are colored and have the quinoid structure. The diacetate and the dichloride are derivatives ol the lactoid modification. 6. Sulfonefluorescin, its zinc salt and its diacetate have been made. They are colorless. Sulfonefluoresciw is very readily oxidized by the air to sulfonefluorescein. 7. With ammonia, sulfonefluorescein forms a stable mono-ammonium salt. 8. Dibromo-sulfonefluorescein and di-iodo-sulfonefluorescein have been made and studied. Like sulfonefluoresceinthey are tautomeric substances, having themselves the colored quinoid structure and yielding diacetates having the lactoid structure. The tetrabromo-sulfonefluorescein described by Sisley could not be made. 9. With ammonia, dibromo-sulfonefluorescein forms a stable monoammonium salt. 10. It has been shown that the fluorescence of sulfonefluorescein is about 10% more intense than that of fluorescein. ITHACA, NEW YORK [CONTRIBUTION FROM THE CHEMICAL LABORATORIES OF COLUMBIA UNIVERSITY, N O .
4451
RESEARCHES ON SELENIUM ORGANIC COMPOUNDS. IV THE SYNTHESIS OF BENZO-BIS-SELENAZOLES AND SELENAZOLO-BENZOTHIAZOLES,NEW HETEROCYCLIC SYSTEMS BY MARSTON TAYLOR BOGERTAND HORACE H. HOPKINS RECCIVBD APRIL16, 1924
PUBLISHED AUGUST6 , 1924
Introductory Benzo-bis-thiazoles (1) have been described previously, but benzobis-selenazoles (11) and selenazolo-benzothiazoles (111)have been unknown hitherto.
The synthesis of derivatives of heterocycles I1 and I11 has been accoinplished by fusion of the 6-benzalamino-2-phenyl-benzoselenazolewith selenium or sulfur.
Pe\ //CCGHS N
C,Hd2N' \CBH~,
4- 2s ---f C&CCC~HI 4- HzS
Aug., 1924
1913
SEIJ$NO-HETEROCYCLIC SYSTEMS
The selenazolo-benzothiazole is interesting on account of its being simultaneously both a thiazole and a selenazole. Hence, it offers an excellent opportunity to compare the behavior of these two cycles toward various reagents. The synthesis of this selenazolo-benzothiazole from the benzalaminobenzoselenazolewas carried out many times. I n one of these experiments, run exactly like the others so far as we could see, the reaction pursued a different course and, instead of the selenazolo-benzothiazole, there was obtained a new base, C27HlsN2S2Se, which when nitrated yielded a product whose analysis gave figures agreeing with those for a simple dinitro derivative. But when this supposititious dinitro derivative was reduced with tin and hydrochloric acid, its oxygen was replaced by hydrogen and an atom of sulfur was removed in the form, of hydrogen sulfide, leaving a compound, C27H20N4SSe.In spite of numerous attempts, we were unable to get any more of this C27HlsN2S2Se compound, and are still in the dark as to its character. As further proof of the structure assigned to these new heterocycles, the diphenyl-benzo-bis-selenazole was synthesized also from dibenzalp-phenylenediamine. Attempts to carry out analogous reactions with 6-furalamino-2-pheny1benzoselenazole failed, because fusion of this compound with either sulfur or selenium decomposed it. Experimental Part CGHSCH :X,pfSe,
6-Benzalamino-2-phenyl-benzoselenazole,
C.CBH,.-As pre-
